A sheet feed apparatus, which can store a large number of sheets, may be attached to an image forming apparatus such as printing machine and copying machine, to supply sheets to the image forming apparatus.
In general, an image forming apparatus (e.g., high-speed printing/copying machine) may include a sheet feed section, which can store a large quantity of sheets, or attach a sheet feed table at a lower part of the image forming apparatus to realize a greater capacity for copying/printing operations with a relatively higher speed. Accordingly, such image forming apparatus may tend to become relatively greater in size such as in height.
An image forming apparatus using electrophotography may include a fixing unit for fixing un-fixed toner image on sheets.
In case of a high speed printing type, the fixing unit may need to fix toner images on a greater number of sheets per a given unit time. In order to suppress failure of fixing operations, the fixing unit may need a fixing member having a greater heat capacity, which may lead to a size increase of a fixing roller such as a greater radius. Such a size increase of the fixing unit may not be preferable from a viewpoint of manufacturing cost or the like.
Furthermore, such image forming apparatus may need to include a toner bottle having a greater capacity to store toner particles, which may be needed to provide a large capacity for printing operations. For example, a full color image forming apparatus may need three or four color toner bottles, by which a size of the image forming apparatus may become increased such as in height.
Furthermore, an image forming apparatus may include a document scanning unit having an automatic document feeder (ADF), in general, by which a size of the image forming apparatus may become further greater.
However, such image forming apparatus having a relatively greater size or dimension may degrade a user operability of document scanning unit and ADF disposed at a top part of the image forming apparatus or there may be increased difficulty when attaching the document scanning unit or ADF on the image forming apparatus.
In conventional image forming system, a sheet feed apparatus having a large capacity for accommodating sheets may be attached to the image forming apparatus to simply supply greater number of sheets to the image forming apparatus with less consideration on user operability of image forming apparatus or image forming system.
Furthermore, such image forming apparatus (e.g., copying machine) may include a manual feed tray, which may be protruded from the lateral side of the image forming apparatus.
If a sheet feed apparatus having a large capacity for accommodating sheets may be attached to such image forming apparatus side by side, the sheet feed apparatus may need to allocate a given space in its body or the like so that the manual feed tray may not interfere with the body of the sheet feed apparatus. Such space may unfavorably increase a width dimension of the sheet feed apparatus.
Furthermore, such manual feed tray of the image forming apparatus may constrain a height of sheet feed apparatus, which may not be preferable from a viewpoint of storing a large number of sheets.